This project?s goal is to develop and test an application that uses Artificial Intelligence (AI) to improve consistency and quality of RT treatment plans for prostate cancer. By understanding expert planner preferences in structure contouring and treatment planning, and combining this rationale with data amassed in NRG clinical trials, AI models will be trained to produce contours and treatment plans achieving consensus amongst experts and optimal quality of life outcomes based on more clinical evidence than any one expert?s input. Overall, this project will meet a need for improved treatment planning for prostate cancer at reduced economic cost. This AI system will generate treatment plans that will provide a standard which may be compared against those generated by human planners; in time, as teams at individual institutions who employ the product develop greater experience with the system, their engagement will foster the achievement of plans at higher quality with lower investment of human capital, thereby improving quality of care while reducing costs.